1. Field of the Invention
The invention relates to an end switch for use with a shaft and a drive for driving the shaft through relatively large number of 360.degree. angular rotations wherein the switch includes a spindle-like drive means responsive to the shaft for moving a switching member in guided fashion parallel thereto so as to bring a stop face of the member into engagement with a contact of a stationary switch at the end of the shaft rotation.
2. Description of the Prior Art
German Auslegeschrift No. 25 11 603 discloses an end switch of this type wherein during the entire angular rotation of the shaft the switching member is guided to its point of impact with the contact of a stationary switch analogously to a nut running on a threaded spindle. With this arrangement, a given switching-off point is realized through the use of a pinion which can be disengaged axially from the outside by means of a loose tool and which is sitated between the threaded spindle and the drive of the shaft for releasing the switch contact. In the adjustment process, a desired end position is approached by the drive and at the desired position of the driven shaft, the threaded spindle is engaged again.
In another known end switch disclosed in German Offenlegungsschrift No. 25 12 102, the entire angular rotation of the driven shaft is reduced at maximum, via a multistage spur gear reduction box, to a single revolution of at least one cam. In particular, the output of the reduction box is coupled via a driving disc to the cam, the cam being adjustably settable in its position relative to the driving disc from the outside via a setting pin built into the end switch.
It is an object of the present invention to provide an end switch of the above type which is highly accurate in spite of having to respond to a relatively large number of (i.e., at least 60) 360.degree. angular shaft rotations.